Cutting threads in Titanium

I have some Ti plate of metal with threads that have only been partially cut. The bolt goes in for a the first half dozen turns and then sticks.

The thread looks like it has been cut all the way. I put a soft bolt into it and forced it a bit when it started to stick. When I took the bolt out most of the thread was still okay but the ends of the thread were blunted.

I don’t really know the process for putting threads into metal but I guess you run a machine bit through the hole gradually cutting away more of the metal to form the thread. it looks like they didn’t bother running the whole way through on the final couple of runs.

If any of this makes any sense, can you suggest what I can do to fix the problem? Will a local machine shop be able to finish the thread making?

This should be a temporary problem while I wait for replacement parts but i have been without the bike a while now and am getting frustrated.

Stop buying cheap rubbish bikes.

Is it the female thread that is not right? If so get a tap of the right size and run it thru – a engineering shop will have one and its a five minute job

A tap

What size thread ?
A machine shop would likely cut it with a machine tap, loads of suds (coolant) or even thread mill if it were on a CNC. They’d drill a hole sized for the finish tap size & pitch.
Eg:- M6x1.0 – 5.0 hole…M8x1.5 = 6.5mm hole etc.
Either way they’d almost certainly use coated taps on Ti, as well as coated drills / solid carbide drills.

You could get hold of a hand tapping kit, this has usually three taps that gradually take the thread out to size.
Failing that you’ll need a decent tap, a tap wrench & plenty of Rocol.
And its just a case of taking your time.

Anyone know of a decent machine shop who would do this around Southampton?

Perhaps could borrow one/get it done at a car/hgv garage.